A communication system includes a collection of components that communicate, manipulate, and process information in a variety of ways. This system may support different access technologies, such as frame relay, circuit services, and new and evolving connection-based or connectionless services, that communicate information, such as data, voice, and video. Switches in the communication systems employ hardware and software to route information generated by access technologies to an intended destination.
In such communication switches, a to-switch port processor may receive various data cells over multiple connections or links. Each data cell may have a header which contains multiple bits of information used in processing the data cell. In particular, the header may comprise a 12-bit virtual path identification (VPI) field and a 16-bit virtual channel identification (VCI) field. Together, the VPI field and VCI field form a 28-bit identifier for the data cell. The 28 bits of information yield 2.sup.28 =268,435,456 combinations for the identifier. Typically, a data cell is processed according to a queue descriptor associated with its VPI/VCI identifier. It is extremely expensive, however, to map all of the combinations for the VPI/VCI identifier in a look-up table which includes a separate queue descriptor for each combination.